9.1 How do I make sure that my post has the right
topic?

When a list administrator defines a topic, he or she sets three things:

a topic name

a regular expression (regexp)

a description

You can view this information by logging in to your member options page.
(See Section 3.1 for more details on how to do this.) and
clicking on the "details" link for any topic that interests you.

To post on a given topic, you need to make sure that the
Keywords: or Subject: headers in a message
match the regular expression for that topic.
Regular expressions can actually be fairly complex, so you may want to
just ask the list administrator if you don't know how to make
heads or tails of the expression given.

Most Mailman topic expressions will be fairly simple regular expressions, so
in this document we will simply give you some common examples. Regular
expressions are a bit too complex to teach in a few lines here, so if you
really want to understand how the regular expressions work, you should
find a tutorial or reference elsewhere. (For example, DevShed has a decent
tutorial at
http://www.devshed.com/Server_Side/Administration/RegExp/)

Here are some examples of possible regular expressions and matching lines:

Regular expression

Matching lines

zuff

Keywords: zuff

zuff

Keywords: ZUFF

zuff

Keywords: Zuff

zuff

Keywords: amaryllis, zuff, applesauce

zuff

Subject: [zuff] Do you have the right stuff for zuff?

zuff

Subject: Do you have the right stuff for zuff?

zuff

Subject: What is zuff?

\[zuff\]

Keywords: [zuff]

\[zuff\]

Subject: [zuff] Do you have the right stuff?

\[zuff\]

Subject: Online zuff tutorials (was Re: [zuff] What is zuff?)

A few notes:

The matching is case-insensitive, so if zuff matches, so will ZUFF,
zuFF, and any other variations in capitalization.

Some characters have special meaning in a regular expression, so
to match those characters specifically, they must be "escaped" with a
backslash (\). As you can see in the above example,
[ and ] are such characters. (Others include ".", "?", and "*").
The backslash is also used for other things (I wasn't kidding about
regular expressions being complex: consult other documentation
for details about other uses of the backslash character), but this
is the most likely use in a topic expression.